Aviation complex (7)
I believe the answer is:
airport
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">aviation complex</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for airport that I've seen before include "Strange pit roar in the travel terminal" , "Aviation centre" , "Heathrow, for example" , "Charles de Gaulle, for instance" , "E.g. Prestwick, Gatwick" .)